Relationship between human leukocyte antigen‐DRB1 and autoimmune hepatitis type I in Chinese patients

AIM: To analyze the association of human leukocyte antigen (HLA)-DRB1 with autoimmune hepatitis type I (AIH) among Chinese patients in the Shanghai area. METHODS: In 32 patients and 48 healthy controls, polymerase chain reaction amplified with sequence-specific primers (PCR-SSP) was performed to elucidate the relevance of certain alleles or polymorphic sequences of HLA-DRB1 with autoimmune hepatitis. RESULTS: The HLA-DRB1 typing by PCR-SSP showed that DR4 had a significantly increased frequency among patients with AIH versus that of healthy controls (46.9 vs 20.8%; relative risk = 3.35, P = 0.014). In the subtypes of DR4, there was a trend of an increase in the gene frequency of DRB1*0405 in patients with AIH versus that of healthy controls (21.9 vs 6.3%, P = 0.04, but corrected P (Pc) = 0.08). In addition, our analysis indicated a significant increase in the alleles frequency encoding Leu-Leu-Glu-Gln-Lys-Arg (LLEQRR) from the third hyperpolymorphic region (HVR3) of DR4 in the patients with AIH (86.7% of DR4 positive patients vs 40.0% in DR4 positive controls, P = 0.016, Pc = 0.028, relative risk (RR) = 9.75). CONCLUSION: Type I AIH among Chinese patients is associated with HLA-DR4. There is a relevance of type I AIH and LLEQRR sequence within the third hyperpolymorphic region of the DRB1 allele.